Not Applicable.
Not Applicable.
The present invention relates in general to STI measuring and more particularly concerns novel apparatus and techniques for measuring speech transmission intelligibility (STI).
For background, reference is made to the Bruel and Kjaer Speech Transmission Meter Type 3361 consisting of Transmitter Type 4425 Receiver Type 4419 that is commercially available and the manual therefor, all incorporated by reference herein. Reference is also made to the Gold Line Model DSP30/DSP30A audio spectrum analyzer and the manual therefor, all incorporated by reference herein.
RASTI (Rapid Speech Transmission Index) relates to a method of measuring speech intelligibility. The method is based on measuring the reduction in signal modulation between a source of speech, such as a loudspeaker, and listeners. The aforesaid Speech Transmission Meter Type 3361 measures RASTI values directly using the Transmitter Type 4225 for sending a special test signal, and Receiver Type 4419 for analyzing the received signal and calculating the RASTI value.
It is an important object of the invention to provide improved methods and means for measuring STI.
According to the invention, a handheld sound analyzer includes a stored Speech Transmission Index (STI) measurement algorithm and a selector for processing a received test sound signal to cause the analyzer to indicate the STI of the received test sound signal. The test sound signal is typically provided by an audio test signal source, such as comprising a CD, tape, MP-3, or other suitable storage medium, having a known audio test signal related to the STI measurement algorithm that is transduced by a source of the test sound signal, such as a loudspeaker, and received by a microphone of the handheld analyzer that transduces the received sound signal into a corresponding electrical test signal that is analyzed in accordance with the stored STI measurement algorithm to produce an indication of the STI between the loudspeaker and the analyzer microphone.
Numerous other features, objects and advantages of the invention will become apparent from the following detailed description when read in connection with the accompanying drawing.